Manufacture of shoes



Aug 189 1953 AKIRA OTSUKA MANUFACTURE oF sHoEs Patented Aug. 18, 1953UNITED STATES Aram OFFICE Application October 13, 1950, Serial No.189,940

In Japan February 22, 1950 1 Claim. l

This invention relates to improvements in the manufacture of shoes.

In the ordinary method, an upper (including a box toe,.counter etc.depending on locations) is lasted to a last and insole by means of alasting machine in the well-known manner, that is, they are temporarilynailed together by a series of nails. Then, a lip, or rib, which hasalready been formed on said insole, the lower edge of the upper and awelt are welted together by means of a welting machine. On the otherhand, however, the sewing needle of the welting machine, which extendsbeyond the nails used for the temporary nailing, breaks down actuallyvery often in collision with those nails, while too much absorption inthe `prevention of such break-down will result in the failure ofproducts, necessitating re-sewing and reducing operating efficiency.

On the other hand, shoes should preferably have cheap wrappers which areeasy to fix and will prevent stains and outside damages during theirWorking processes and before they arrive at consumers in the market.

The object of this invention is to provide an improved method ofmanufacturing shoes, wherein a separate means for securing lasted partsis pro-vided which can safely be sewed in together at the time ofWeltng, so that said nails which prove outstanding obstacles in weltingas above mentioned can be drawn out before Welting, this means beingmade to act also as said preferable wrappers, and thus shoes providedwith superior wrappers can be manufactured easily and efhciently.

In the present invention an upper lasted to a last and insole isinserted into a nearly enclosed sack the film of which tends to contractat higher temperatures without splitting or folding in itself, said filmcontracting under heat down to the whole outer surface of said contentsso as to maintain them in lasted condition at normal temperatures,enabling drawing out nails used in lasting, before welting, and forminga protective wrapper of the shoe in close contact therewith.

In the description of this invention reference is had to theaccompanying drawings, of which:

Figure 1 is a perspective View showing parts of a shoe to be made,inserted in a sack which will provide a securing means of the contentsand form a wrapper of the shoe, according to the invention.

Figure 2 is a sectional view on a large scale taken substantially on theline II--II of Figure with the atmosphere through edge 5 which is" 1showing a welted shoe after nails are drawn out, lthe parts beingsuitably exaggerated, for illustration.

In the drawings, an upper l is lasted to last L and insole 2. The loweredge of upper I comes down to a lip, or rib, 3 provided at the outerperipheral edge of insole 2 located at the bottom of last IJ, where saidupper l is temporarily fixed to insole 2 and last L by means of nails 4.In Fig. 2 nails 4 are already drawn out in practice according to thisinvention, but shown in dotted line. According to this invention, theparts of a shoe thus assembled is enclosed loose in sack 5 made forexample of stabilized rubber hydrohalide, allowing a littlecommunication not to be sealed tightly. When the whole assembly isheated up to -80 C. in the atmosphere by means of steam, the film ofsack 5 of stabilized rubber hydrohalide will contract without causingcracks or folds in itself due to its characteristics, resulting in avery uniform and fine close contact with the outer surface of thecontents by eliminating air layers among them, through said smallclearance at edge 5 of sack 5. However, due to its characteristics, saidlm will not adhere to the shoe, and no chemical change will be caused tothe component members of the shoe. The film of sack 5 thus comes inclose contact with the whole outer surface of the contents. However, itwill not be automatically in contact with the insides of hollows, thatis, a space will remain at a position like 6. When the assembly isrestored to the normal temperatures in the atmosphere, the film Will setas it is, compressing the contents rmly inwards in every direction dueto its own tensile force. This process of making a close contact of theilm by heating is very simple and can be completed in a matter of 10 to20 seconds, without requiring any skill. Here the duty of said nails 4is over, and they can be drawn out by breaking through film 5 by meansof pincers. There is no fear of causing cracks and splits from the edgeof the small holes opened at this time and of growth of them, due to thecharacteristics of the stabilized rubber hydrohalide although said filmcompresses the contents in every direction.

Then the assembly together with the film is welted in a welting machinein the well-known manner and a welt 8 is stitched to the assembly. (Atthis time, the film is automatically cut off inside the insole lip, orrib, at 'I by the channel guide of the Welting machine.) However, no

cracks or splits will be caused at all on the upper leather side of theseam as just mentioned above. After that, a bottom filler is tted inspace 6. Then the well-known process will be adopted, and the upper partof film 5 will finally be cut on" to take the last out, Without causingany cracks or splits in the film itself. Thus the outer surface of theshoe over the upper leather will remain covered by the lm of .stabilizedrubber hydrohalide close contact. The shoes can thus be well protectedfrom stains and outside damages until the sack is removed. Sincestabilized rubber hydrohalide is highly proof against water, oil andchemicals, is inert to the component members of the shoe and issemi-transparent, operators can work them without worry. As it readilyreveals the contents, it is very convenient and handy. The lm isespecially suitable for shoes With White and other thin colored leather,linen or fabric upper members.

Though stabilized rubber hydrohalide has been taken up here as thematerial for Isuch sacks, any other materials of similar characteristics:can be 4safely used.

yln general vthe requirements of the film :of such sack "can beenumerated a-s follows:

.(1) It :should have the characteristics of auto matically contracting{downto the shape .fof contour Vunder steam or heat Without causingcracks, folds or splits.

`(2) iIt should have @a .considerable mechanical strength at:normal-temperatures.and.shouldfhave no .tendency ltoward :easilyallowing `.the growth of cracks and splits from the-small holes, etc.

3) It should be .highly proof :against Water, oil and .chemicals.andshouldbe .inert to ,the component members -of the shoes.

(4) It should have the nature of being formed to the shape of the sack.

(5) It should be cheap enough to be applied to mass production. Thoughthe above embodiment has been shown and described by the Goodyear weltmethod of manufacturing shoes, it will be understood that this inventioncan be applied to any other method of manufacturing shoes, such as McKayor cemented processes, and it is clear that it can be applied not onlyto leather shoes but also to linen and fabric ones as previouslymentioned.

.II .claim:

A method of manufacturing shoes which con- -sis'tfinlfasteniing va shoeupper to a last and insole, inserting the .assembly loosely in a sacl;of sta bilized Yrubber hydrohalide without completely cutting offcommunication of the sack interior -with `tl-ie atmosphere,steam-heating the stabilized rubber hydrohalide to a temperature and for`a time sufficient .to shrink same Ato `closely embrace the surface ofthe 'contained assemli'ly Without .causing cracking, restoring 'theYassembly to normal atmospheric -temperature and removn ing thetastenings, i.We'lfting the upper vwhile enclosed -by the stabilizedrubber hydronal'ide sack, and ythereafter removing the last.

AKIRA OTSUKA.

:References Cited in v.the le of this patent 'UNITED STATES PATENTSNumber Name Date 2,168,651 McCoy Aug. v8, 1939 2,182,022 Griswold Dec.5, 1939 2,385,257 Cavallito Sept. 18, 1945

